Voice over Long-Term Evolution and Video over Long-Term Evolution (VoLTE) are standards for voice and video communication and based on LTE network and IP Multimedia Subsystem (IMS) network, where the LTE network is used for service access, and the IMS network is used for service control. The VoLTE supports various communication services, such as High Definition (HD) voice or HD video, and is compatible with voice in 2G/3G network.
In VoLTE networks of different operators, video resolutions, frame rates or bit rates adapted for a same mobile terminal are different. For example, according to Quality of Service (QoS) parameter analysis sent by Evolved Packet System (EPS) network when a video call is initiated, a video bandwidth (i.e., 2112 kbps) configured by a VoLTE network of China Mobile Communications Corporation (CMCC) is six times that (i.e., 288 kbps) configured by a VoLTE network of Indian Reliance Communications. Therefore, both the video resolutions and the frame rates are different in the VoLTE networks of the two operators. To a same mobile terminal, if the video resolution is 480*640, the frame rate is 30 FPS and the bit rate is 1.2 Mbps, a video can be played fluently in the CMCC network, while the video is hardly watched in the Reliance network due to serious mosaics.
Inventors found that existing techniques have at least following disadvantages. To a same mobile terminal, as the video resolutions, the frame rates and the bit rates adapted for different VoLTE networks are different, the video calling quality may be good in one VoLTE network but relatively poor in another VoLTE network. That is, in the existing techniques, it is difficult to obtain good video calling quality in different VoLTE networks.